The International Brigades were military units set up by the Communist International to assist the Popular Front government of the Second Spanish Republic during the Spanish Civil War. The organization existed for two years, from 1936 until 1938. It is estimated that during the entire war, between 40,000 and 59,000 members served in the International Brigades, including some 10,000 who died in combat. Beyond the Spanish Civil War, "International Brigades" is also sometimes used interchangeably with the term foreign legion in reference to military units comprising foreigners who volunteer to fight in the military of another state, often in times of war.
The International Brigades (IB) were volunteer military units of foreigners who fought on the side of the Second Spanish Republic during the Spanish Civil War. The number of combatant volunteers has been estimated at between 32,000–35,000, though with no more than about 20,000 active at any one time. A further 10,000 people probably participated in non-combatant roles and about 3,000–5,000 foreigners were members of CNT or POUM. They came from a claimed "53 nations" to fight against the Spanish Nationalist forces led by General Francisco Franco and assisted by German and Italian forces.
Mixed brigade was a basic tactical military unit of the Republican army during the Spanish Civil War. It was initially designed as “pocket division”, an innovative maneuverable combined-arms formation. Because of high saturation with specialized troops and services it would have resembled a division, but in terms of manpower it would have been much smaller and amount to some 3,700 men.
The 224th Mixed Brigade was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in summer 1937 in Catalonia from scattered Coastal Defence units and had four battalions: the 893, 894, 895 and 896.
The 26th Division was a division of the Spanish Republican Army in the Spanish Civil War. It was formed in April 1937 in Aragon from the militarized Columna Durruti during the reorganization of the Spanish Republican Armed Forces.
The 11th Division was a division of the Spanish Republican Army in the Spanish Civil War. It was formed in January 1937 in Madrid beginning with the 1st Mixed Brigade which in turn had originated in the Fifth Regiment.
The 242nd Mixed Brigade, was a short-lived mixed brigade of the Spanish Republican Army in the Spanish Civil War.
The 228th Mixed Brigade, was a short-lived mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in the last months of the Civil War with battalions belonging to the Carabineros corps. Its first and only leader was the Carabineros Commander Miguel Bascuñana Sánchez.
The 3rd Mixed Brigade, was one of the earliest mixed brigades of the Spanish Republican Army in the Spanish Civil War. It was formed in the fall of 1936 with battalions of the Carabineros corps and saw major action right away in the Defence of Madrid. This brigade also included female combatants —such as Sergeant "La Chata"— and would take part in most of the major battles of the Spanish Civil War, except in the Battle of Jarama.
The 109th Mixed Brigade, was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in the spring of 1937 in Utiel with four battalions, the 433, 434, 435 and 436.
The 175th Mixed Brigade, was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. Its number was formerly corresponding to the 10th Santander Brigade, a unit operating in Santander, Spain but was assigned to a new unit in the spring of 1938 in Valencia Province and had four battalions, 697, 698, 699 and 700.
The 86th Mixed Brigade, was a mixed brigade of the Spanish Republican Army in the Spanish Civil War. It was formed in March 1937 with battalions of the Carabineros corps. Until its demise it operated mostly in the Sierra Morena area, at the southern limits of the territory held by the Republic.
The CL International Brigade or 150th International Brigade, also known as "Dabrowski Brigade", was a military unit of the International Brigades during the Spanish Civil War. Its members were mostly Polish, but there was also a Spanish battalion, as well as a Hungarian section.
The 153rd Mixed Brigade was a unit of the Spanish Civil War that took part in the Spanish Civil War. Formed around the old Land and Freedom Column, the unit took part in the battles of Belchite, Aragon and Segre.
The 140th Mixed Brigade was a unit of the Spanish Republican Army created during the Spanish Civil War. Throughout the war it operated on the fronts of Aragon, Segre, Ebro and Catalonia.
The 141st Mixed Brigade was a unit of the Spanish Republican Army during the Spanish Civil War. It participated in the Battle of Belchite, Aragon Offensive, Battle of the Segre and the Catalonia Offensive.
The 104th Mixed Brigade was a unit of the Spanish Republican Army created during the Spanish Civil War. Throughout the war it acted on the Extremadura, Aragon and Catalonia fronts.
The 133rd Mixed Brigade was a unit of the Spanish Republican Army that participated in the Spanish Civil War, deployed on the fronts of Aragon, Segre and Catalonia.
The 145th Mixed Brigade was a unit of the Spanish Republican Army created during the Spanish Civil War. Throughout the war, it operated on the Aragon, Segre and Catalonia fronts, although it did not play a relevant role.
The 149th Mixed Brigade was a unit of the Spanish Republican Army created during the Spanish Civil War. Deployed on the fronts of Madrid, Aragon and Catalonia, the brigade did not play a relevant role in the war.
Spain 
International Brigades 
